Missing Medicare document cost Philadelphia woman hundreds before refund arrived. What enrollees should know.

When Linda Hagdorn applied for Medicare Part B earlier this year, she believed she had submitted everything needed.

Instead, the Philadelphia-area woman says one missing document triggered months of higher monthly charges and repeated calls to the Social Security Administration before the issue was finally resolved.

"I submitted all the documentation, and I neglected to include verification that I had the insurance," Hagdorn said. "I didn't know. It was an honest mistake."

A common Medicare rule trips up some seniors

Medicare generally requires people to enroll in Part B, which covers doctor visits and other outpatient medical services, when they first become eligible.

However, people covered under a spouse's or their own current employer health plan can qualify for a Special Enrollment Period and avoid late enrollment penalties if they provide documentation proving that coverage, according to AARP. 

Hagdorn said she delayed enrolling because she was covered under her husband's employer-sponsored health insurance.

When she applied for Part B in January, she accidentally left out documentation showing she had maintained that coverage, she said.

Soon afterward, she received notice that she would be charged a higher premium.

"I didn't think they were going to penalize me as a senior citizen," Hagdorn said.

Extra money came out of her check every month

Hagdorn said about $102 in additional charges was deducted from her Social Security payment each month while she tried to resolve the issue.

According to Medicare, late enrollment penalties are added to monthly premiums and can continue for as long as a beneficiary maintains that coverage. In many cases, the Part B penalty equals 10% of the standard premium for each full 12-month period someone could have enrolled but did not.

Hagdorn said she quickly obtained the missing documentation and submitted it, but the penalty remained in place.

She said she repeatedly contacted Social Security over the next six months.

"Yes, Mrs. Hagdorn, all of your paperwork is in here, but a human needs to [review it]," she recalled being told. "That was insulting to me because I was kind of like, you don't have humans there? Aren't I talking to a human?"

She said representatives were courteous but unable to provide answers about when a final decision would be made.

"The agents were nice. They were kind to me. They weren't helping me," she said.

Resolution came after contacting CBS News Philadelphia

After months of unsuccessful attempts, Hagdorn contacted In Your Corner.

Within days, she said two credits totaling $609 appeared in her bank account, and her Medicare premium was corrected. 

"I am so happy," Hagdorn said. "I don't feel that I would be this far if I didn't reach out and ask for help and accept the help."

CBS News Philadelphia asked the Social Security Administration why the matter remained unresolved for months after Hagdorn submitted the requested documentation. A spokesperson declined to comment on an individual case.

Watchdog audit finds broader concerns

Hagdorn's experience comes as a recent Social Security Administration Office of Inspector General audit found problems involving Medicare Part B penalty assessments.

The audit reviewed a sample of Medicare Part B applications and estimated that approximately 12,000 beneficiaries may have had applications processed incorrectly, resulting in roughly $12 million in improperly assessed penalties. The report found errors involving employer-sponsored group health coverage, Special Enrollment Period determinations and other exceptions that can reduce or eliminate penalties.

Investigators also found Medicare enrollment notices did not always clearly explain late enrollment penalties or the consequences of delaying enrollment.

Hagdorn hopes others can learn from her experience

For Hagdorn, the biggest lesson is making sure every required document is submitted and following up quickly if something does not seem right.

She also worries about other seniors who may not realize a mistake has occurred or may struggle to navigate a complicated government process.

"What about my fellow senior citizens?" Hagdorn said. "What if they don't know?"

What Medicare beneficiaries should know

People who delay Medicare Part B enrollment because they are covered by a current employer's health insurance, either their own or a spouse's, generally can avoid late enrollment penalties by documenting that coverage when they enroll. 

Medicare advises beneficiaries to keep records of employer coverage and review enrollment requirements carefully.

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