Which statement about rules on rates for Medicare plans is NOT true?

The statement that is not true regarding rules on rates for Medicare plans is one that implies rates can vary depending on gender or age. In fact, Medicare plans have specific regulations that prohibit discrimination based on age and gender when it comes to setting premiums for Medicare Advantage and Part D plans.

Rates for these plans can vary by geographical location due to differences in the cost of healthcare in different regions, and they cannot be influenced by pre-existing conditions, as this is a safeguard of the Medicare program to ensure access to coverage. Additionally, rates are not fixed regardless of a person's circumstances, as they can change based on various factors like region and plan options.