Research · 6 min read
Medicare's Enrollment Periods, and What a Late Part B Penalty Costs
Part B has one seven-month window at the start, a three-month window every January, and an exception for people covered by an employer plan. Missing all three carries a premium increase that the regulation states as a formula, and it does not expire.
Key takeaways
- The Part B initial enrollment period is seven months: three before the month of first eligibility, that month, and three after.
- The general enrollment period is January through March of each calendar year, so a missed initial window recurs annually as a chance to enroll.
- The late enrollment increase is ten percent of the standard monthly premium for each full twelve months in the periods the computation regulations define, and those regulations state no expiration.
- Months spent covered by a group health plan by reason of current employment status, and months of coverage taken during a special enrollment period, are excluded from the count for premiums due since the mid-1980s.
- The special enrollment period for someone 65 or over requires coverage by reason of the individual's or a spouse's current employment status — the regulation's phrasing, and the reason retiree coverage is treated differently.
- Because the surcharge attaches to the standard monthly premium, which is promulgated each September for the following calendar year, its dollar amount moves from year to year.
Answer first: three windows, and a permanent surcharge for missing them
The initial enrollment period for Part B is, in the regulation's words, "the 7-month period that begins 3 months before the month an individual first meets the eligibility requirements" and "ends 3 months after that first month of eligibility." Three months before, the month itself, three months after.
If that window closes unused, the general enrollment period is next. The regulation states it in one sentence: "the general enrollment period is January through March of each calendar year." It recurs annually, so a missed initial window is not permanently disqualifying.
Between them sits an exception for people whose coverage came from work. There is a special enrollment period related to coverage under group health plans, and the point of it is that time spent covered by such a plan by reason of current employment status does not count against the person.
The consequence of enrolling late without that exception is a premium increase set out in a single sentence: for an individual who enrolls after the initial enrollment period expires or reenrolls after a coverage period ends, "the standard monthly premium determined under § 408.20 is increased by ten percent for each full twelve months" in the periods the regulation specifies. Nothing in that sentence limits how long the increase lasts.
How the countable months are actually counted
The ten percent is not applied to elapsed calendar time in the loose sense. The computation regulation defines the period as "the number of months elapsed between the close of the individual's initial enrollment period and the close of the enrollment period in which he or she first enrolled" — and then excludes a specific list of months.
Two of those exclusions do most of the work today. For premiums due for months beginning with June 1986, the regulation excludes any months after December 1982 during which the individual was age 65 or over and covered under a group health plan by reason of current employment status, and it excludes any months of Part B coverage for which the individual enrolled during a special enrollment period. A parallel exclusion, effective for premiums due from January 2007, covers months in which the individual met the conditions of the newer special enrollment period provision.
The rest of the exclusion list is largely historical: three months in early 1968, months before January 1973 blocked by an old three-year enrollment limit, months in or before a period of coverage under a State buy-in agreement, months before a person under 65 began their current continuous period of Part A entitlement, and, for someone 65 or older, any month before the month they turned 65. A separate short section handles the unusual cohort who enrolled during the continuous open enrollment that ran between April 1 and September 30, 1981.
Because the count runs to the close of the enrollment period in which the person first enrolled, and because it is expressed in full twelve-month blocks, a delay of eleven months adds nothing and a delay of thirteen adds one increment. The structure is stepwise, not proportional.
The employment exception, and the conditions attached to it
The special enrollment period regulation for Part B sets out a general rule and then two sets of special rules. The general rule has three requirements. The individual must be eligible to enroll on the basis of age or disability, but not on the basis of end-stage renal disease. When first eligible for coverage — the regulation pins this to "the 4th month of their initial enrollment period" — they must have been covered under a group health plan or large group health plan on the basis of current employment status, or else they enrolled during their initial enrollment period. And for all months thereafter, they must have maintained coverage under either Part B or such a plan.
The special rule for someone age 65 or over is short and specific: for an individual who is or was covered under a group health plan, "coverage must be by reason of the current employment status of the individual or the individual's spouse." Retiree coverage is not current employment status, and the regulation's language is written around that distinction.
Part B borrows its duration and effective-date rules from the corresponding Part A provision. That provision states that the special enrollment period includes any month during any part of which the individual is enrolled in a qualifying plan by reason of current employment status, and that it "ends on the last day of the eighth consecutive month during which the individual is at no time enrolled" in such a plan by reason of current employment status.
Effective dates follow the timing of the enrollment. If the individual enrolls in a month during any part of which they were still covered on the basis of current employment status, or in the first full month after that coverage ends, coverage begins on the first day of the month of enrollment or, at the individual's option, on the first day of any of the three following months. If they enroll in any other month of the special period, coverage begins on the first day of the month following enrollment.
There is also a use-it rule. Generally, if an individual fails to enroll during any available special enrollment period, they are not entitled to any additional ones — with an exception where the failure to enroll happened because plan coverage was restored before that period ended.
What the ten percent is ten percent of
The penalty regulation increases "the standard monthly premium determined under § 408.20." That section describes how the standard monthly premium is set: since a 1983 amendment, the Secretary promulgates it in September to be effective for the twelve months beginning the following January, and the standard premium "applies to individuals who enroll during their initial enrollment periods," while "in other situations, that premium may be increased or decreased as specified in this subpart."
So the surcharge attaches to a figure that changes annually, which means the dollar amount of a penalty moves with the standard premium rather than being frozen at the level in effect when the person enrolled.
For the current year, the medicare.gov page on Medicare costs states a Part B premium of "$202.90 each month (or higher depending on your income)" and a Part B deductible of "$283 before Original Medicare starts to pay," with coinsurance "usually 20% of the cost." Those figures come from that page and describe the standard amounts, not any individual's amount. The regulations quoted in this article set the method by which a penalty is computed; they do not state a current-year premium.
Reading the rules together
The statute behind the special enrollment period is worth noticing because it draws the same line the regulation does. It describes a special enrollment period for an individual who, at the time they first satisfied the eligibility conditions, was enrolled in a group health plan by reason of their own or their spouse's current employment status and elected not to enroll during their initial enrollment period. It also describes a separate six-month special enrollment period, beginning on the first day of the month that includes the date of termination, for certain individuals whose continuous enrollment under a group health plan is involuntarily terminated at a time when that enrollment is not by reason of current employment.
Set side by side, the pieces form a single mechanism. The initial enrollment period is the default. The general enrollment period each January through March is the fallback. The special enrollment period is the escape hatch for people whose delay was caused by employment-based coverage — and it is also the thing that removes those months from the penalty computation, which is why the two regulations cross-reference each other.
What none of these provisions do is forgive a delay for any other reason. The penalty regulation states one arithmetic rule and the computation regulation states a closed list of excluded months. A month that is not on that list counts.
Whether a particular person's months fall inside an exclusion is a determination made on their record by the agency administering the enrollment, not something a rule text can settle in advance.
Sources
- 42 CFR § 407.14 — Initial enrollment periodThe seven-month duration of the initial enrollment period and the deemed initial enrollment period for someone misled by erroneous documentary evidence about their age.
- 42 CFR § 407.15 — General enrollment periodThat the general enrollment period is January through March of each calendar year, and the one-time unlimited period between April 1 and September 30, 1981.
- 42 CFR § 407.20 — Special enrollment period related to coverage under group health plansThe three general conditions for the Part B special enrollment period, including the reference to the fourth month of the initial enrollment period and the requirement to maintain coverage thereafter, and the special rule that coverage for someone 65 or over must be by reason of the individual's or spouse's current employment status.
- 42 CFR § 406.24 — Special enrollment period related to coverage under group health plansThe definition of a special enrollment period, its duration ending on the last day of the eighth consecutive month without qualifying coverage, the effective-date options, and the rule that failing to enroll during an available special enrollment period generally forecloses additional ones.
- 42 CFR § 408.20 — Monthly premiumsThat the standard monthly premium is promulgated in September to be effective for the twelve months beginning the following January, that it applies to individuals who enroll during their initial enrollment periods, and that in other situations it may be increased or decreased as the subpart specifies.
- 42 CFR § 408.22 — Increased premiums for late enrollment and for reenrollmentThe ten percent increase for each full twelve months in the periods specified by the computation sections, applied to the standard monthly premium.
- 42 CFR § 408.24 — Individuals who enrolled or reenrolled before April 1, 1981 or after September 30, 1981The definition of the countable period as the months elapsed between the close of the initial enrollment period and the close of the enrollment period in which the individual first enrolled, and the full list of excluded months, including the group-health-plan and special-enrollment-period exclusions effective for premiums due from June 1986 and from January 2007.
- 42 CFR § 408.25 — Individuals who enrolled or reenrolled between April 1 and September 30, 1981The special counting rule for the 1981 continuous open enrollment cohort, during which no three-month general enrollment period existed.
- 42 U.S.C. § 1395p — Enrollment periodsThe statutory special enrollment period for an individual enrolled in a group health plan by reason of their own or a spouse's current employment status who elected not to enroll during the initial enrollment period, and the separate six-month special enrollment period beginning with the month that includes an involuntary termination of certain group health plan coverage not by reason of current employment.
- Medicare costsThe standard Part B premium of $202.90 each month or higher depending on income, the Part B deductible of $283, and Part B coinsurance of usually 20 percent of the cost.
Frequently asked questions
How long is the initial enrollment period for Part B?
Seven months. The regulation defines it as the period that begins three months before the month an individual first meets the eligibility requirements and ends three months after that first month of eligibility. The same section provides for a deemed initial enrollment period where someone failed to enroll because erroneous documentary evidence led them to believe they had not yet reached age 65.
When is the general enrollment period?
January through March of each calendar year, as the regulation states. The section also records a one-time unlimited general enrollment period that existed between April 1 and September 30, 1981.
How is the late enrollment increase calculated?
The regulation increases the standard monthly premium by ten percent for each full twelve months in the periods specified by the computation sections. Those sections count the months elapsed between the close of the initial enrollment period and the close of the enrollment period in which the person first enrolled, then subtract a listed set of months — including, for premiums due since June 1986, months after December 1982 in which the individual was 65 or over and covered under a group health plan by reason of current employment status, and any months of coverage for which the individual enrolled during a special enrollment period.
Does the increase ever stop?
The regulation states the increase without a stated end point, and the increase is applied to the standard monthly premium, which is promulgated annually. Nothing in the sections read for this article provides for the increase to expire after a number of years.
Does employer coverage after retirement count for the special enrollment period?
The regulation's special rule for individuals age 65 or over requires that group health plan coverage be "by reason of the current employment status of the individual or the individual's spouse." The general rule further requires that the person maintained coverage under either Part B or a qualifying plan for all months after first eligibility. Whether particular coverage meets that description is a determination on the individual's record, not a general answer.
How long does the special enrollment period last once employment coverage ends?
Under the duration rule Part B adopts, the special enrollment period includes any month during any part of which the individual is enrolled in a qualifying plan by reason of current employment status, and it ends on the last day of the eighth consecutive month during which the individual is at no time so enrolled. The statute separately describes a six-month special enrollment period beginning with the month that includes the date of an involuntary termination of certain group health plan coverage that was not by reason of current employment.